Cupriferous azo-dyestuffs



United States CUPRIFEROUS AZO-DYESTUFFS Henri Riat, Arlesheim, Switzerland, assignor to Ciba Limited, Basel, Switzerland, a Swiss firm No Drawing. Application March 7, 1955 Serial No. 492,744

Claims priority, application Switzerland March 16, 1954 9 Claims. (Cl. 260-146) N-Ra in which R represents a benzene radical fused in the manner shown to the thiazole ring, R represents a benzene radical bound to the azo linkage in para-position to the thiazole ring, R represents a benzene or napthalene radical, and R also represents a benzene or naphthalene radical, and in which at least one of the radicals R and R contains a sulfonic acid group and the groups --R -N=N, -O-alkyl and -N=N- are present in the 1:3:4-positions of the radical R with an agent yielding copper under conditions such that an ortho:ortho'- dihydroxy-azo-copper complex is formed with the splitting off of the alkoxy group in the ortho-hydroxy-ortho'- alk'oxy-grouping and that the free amino group in the ortho-amino-azo-dyestutf and the azo linkage bound to R undergo ring closure to form the triazolc ring.

The dyestuffs of the Formula 1 can be made by coupling a diazo-compound of an amine of the formula with a middle component of the formula- O-Alkyl H-Ra-NH;

diazotizing the resulting amino-monoazo-dyestuif of the constitution O-Alkyl atent H0 8 NH:

In the above formulae R R and R have the meanings given above in connection with Formula 1.

As initial components there may be used amines of the Formula 3 of which both benzene radicals R and R contain further substituents, for example, halogen atoms such as chlorine, or methoxy or ethoxy groups, but especially methyl groups and/or sulfonic acid groups. Owing to their ready availability and the good results obtained therewith there are especially suitable as initial components monosulfonic acids and disulfonic acids of 2- (4 aminophenyl)-6-methyl-benzthiazole (dehydrothiotoluidine). These compounds correspond to the formula meg O s in which n represents a whole number not greater than 2.

As examples of initial components there may be mentioned: The 2-(4'-aminophenyl)-6-methyl-benzthiazolex-sulfonic acid obtainable by sulfonating 2-(4-aminophenyl)-6-methyl-benzthiazole with concentrated sulfuric acid; 2 (4-arninophenyl)-6-methyl-benzthiazole-3-su1- tonic acid which is obtained by the thermal rearrangement of the acid sulfate of 2-(4-aminophenyl) -6-methylbenzthiazole; 2-(4-aminophenyl)-6-methyl-benzthiazole disulfonic acids, for example, the acid obtained by thermal rearrangement of the acid sulfate of the 2-(4-aminophenyl) 6-methyl'benzthiazole monosulfonic acid obtainable by sulfonating 2-(4-aminophenyl)-6-methylbenzthiazole with concentrated sulfuric acid; and the 2- (4'-aminophenyl)-benzthiazole-x-sulfonic acid obtainable by the sulfonation of 2-(4-arninophenyl)-benzthiazole.

The middle components of the Formula 4 may be of the naphthalene series or advantageously of the benzene series. They contain an alkoxy group, advantageously a methoxy group, which is in orthoposition relatively to the NH -group. As examples of suitable middle components there may be mentioned the following compounds:

Especially valuable dyestuffs are obtained with 1- amino-2-methoxybenzene itself.

The monoazo-dyestuii of the Formula 6 can be obtained by coupling Z-amino-S-hydroxynaphthalene-7- sulfonic acid under acid conditions with a diazo compound of the naphthalene or more especially the benzene series, which advantageously contains a group imparting solubility in water, such as a sulfonio acid amide group;

3 a carboxyl group or especially a sulfonic acid group. The diazo Compounds of the following amines may be mentioned as examples: Aminobenzene, l-amino-Z- methoxybenzene, l-aminobenzene-Z- or -4-carboxylic acid, 1-aminobenzene-3- or -4-sulfonic acid, 1-amino-4- methylbenzene-3-sulfonic acid, 1-amino-benzene-3- or -4- sulfonic acid amide, 2-amino-naphthalene-6-sulfonic acid and 2-aminonaphthalene-4:8-disulfonic acid.

1-In.the manufacture of the dyestufis of the Formula 1 the coupling of the diazotized initial component with the middle component is generally carried out with advantage in a weakly acid to weak-1y alkaline medium, for example, an acetic acid medium or a medium rendered alkaline with an alkali bicarbonate. If the middle component has a low capacity for coupling, it is generally of advantage to couple it in the form of its w-methanesulfonic acid, and subsequently to split oil the ctr-methane sulfonic acid group. This applies, for example, to 1- amino-2-methoxyhenzene. The diazotization of the amino-monoazo-dyestuffs of the Formula 5 can be carried out by methods in themselves known, for example, with the use of hydrochloric acid and sodium nitrite. The diazo-monoazo-compounds so obtained are then coupled inan alkaline medium, for example, a medium rendered alkaline with an alkali carbonate, with the monoazo-dyestufis of the Formula 6, if desired, with the addition of an agent assisting coupling, such as pyridine or picoline.

The treatment with the agent yielding copper may be carried out by the usual methods. In some cases the coppering treatment may be carried out with a salt of divalent copper in a weakly acid aqueous medium. Alternatively, the dyestufis may be metallized by the known method in whichthe metallization is carried out with the use of a copper-tetrammine complex in the presence or absence of an excess of an amine or ammonia for several hours in the vicinity of 100 C. in an aqueous medium. In some cases it is of special advantage to use the process of U. S. Patent No. 2,536,957 in which the coppering is carried out in the presence of an oxyalkylamine, especially ethanolamine, or a copper complex derived from such amine. It is desirable to use an excess of the agent yielding copper, since a part of this agent is necessary as an oxidizing agent for the triazole ring formation which takes place simultaneously with the production of the copper complex.

The new cupriferous dyestufis of this invention correspond to the general formula I N ki-Ra in which R represents a benzene radical fused to the thiazole ring in the manner indicated, R represents a benzene radical bound to the azo linkage in para-position to the thiazole ring, R represents a benzene or naphthalene radical, and R also represents a benzene or naphthalene radical, and in which at least one of the radicals R and R contains a sulfonic acid group and the groups -R -N=N, -OCuand --N=N are present in the 1:3:4-positions of the radical R With regard to the above Formula 8 of the cupriferous dyestuffs, this formula undoubtedly represents the correct stoichiometric proportion of copper and the correct position of the copper atom in the complex, but the distribution of the main and secondary valencies in the complex union of the copper has not yet been established with certainty.

The new cupriferous dyestuifs corresponding to the general Formula 8 and obtainable by the process described above can also be made by using, instead of a .4 dyestufi of the Formula 1 which contains a free amino group, a dyestufi of the Formula 2 which already contains the triazole ring. In order, to prepare the latter dyestufis, dyestuffs of the Formula 1 may be treated with oxidizing agents which do not lead to the formation of copper complexes, or an amino-monoazo-dyestuif of the Formula 5 may be diazotized and coupled with a triazole compound of the formula such as wool, silk, leather, but especially cellulose-containing fibers such as cotton, linen and also artificial silk or staple fibers of regenerated cellulose. The dyestuffs possess a good levelling capacity. The dyeings produced therewith are distinguished by their especially interesting tints and in general by unexpectedly good properties of fastness.

The following examples illustrate the invention, the parts and percentages being by weight:

Example 1 32 parts of 2-(4-aminophenyl)-6-methyl-benzthiazone-x-sulfonic acid (obtainable by sulfonating 2-(4'- aminophenyl)-6-methyl-benthiazole with sulfuric acid containing sulfur trioxide) are dissolved in 200 parts of water with the addition of 5.3 parts of anhydrous sodium carbonate and 6.9 parts of sodium nitrite are added. The solution is slowly run into a mixture of 30 parts of hydrochloric acid of 30 percent strength, 100 parts of water and 100 parts of ice. The whole is stirred for one hour, and then the suspension of the diazo compound, after having been neutralized to a considerable extent with sodium bicarbonate, is introduced into a solution, containing an excess of sodium acetate, of 21.7 parts of 1-amino-2-methoxybenzene-w-methane sulfonic acid, and the whole is stirred at 10 C. until the coupling is finished. The monoazo-dyestutr' is then separated ofi and hydrolyzed by heating it for 2 hours at C. with a sodium hydroxide solution of 4 percent strength. After cooling the mixture to 40 C.,

the precipitated amino-monoazo-dyestufi is filtered ofi, dissolved or suspended in water, 8 parts of sodium nitrite are added, and is further disazotized by pouring in 30 parts of hydrochloric acid of 30 percent strength. The whole is stirred for 2 hours at about 35 C., and the diazo-compound is coupled at 5-10 (3., in a solution rendered alkaline with sodium carbonate or sodium bicarbonate with 40 parts of the monoazo-dyestuff ohtain'ed by coupling diazotized 1-aminobenzene-3-sulfonic acid under acid conditions with Z-amino-S-hydroxynaphthalene-7-sulfonic acid. The coupling is strongly accelerated by the addition of pyridine or picoline. When the coupling is finished, the trisazo-dyestufi is salted out and filtered off.

The dyestufi paste is dissolved in 2000 parts of warm water with the addition of .30 parts of monoethanolamine, and the solution is mixed with an ammoniacal solution of copper sulfate (corresponding to 50 parts of CuS 5H O the whole is heated under reflux, and NW4: while stirring, for hours at 90-95 C. The dyestuff so formed of the formula is isolated and dried. There is obtained a grey powder which dissolves in water with a grey-blue coloration and dyes cotton greenish grey tints.

Further cupriferous dyestuifs, which can be obtained No.6: in the manner described above, are given in the following table. These dyestufis are obtained by coupling the diazoazo compounds of the aniino-monoazo-dyestuifs obtainable from the initial components of column I and the middle components of column II with the orthoamino-monoazo-dyestuffs obtained from the diazo-components of column III and 2-amino-5-hydroxy-naphthalcne-7-sulfonic acid, and converting the trisazo-dyestuifs in the manner described above into the cupriferous azo-triazolc-compounds.

s no, Ndn p BOt Example 2 The diazo-monoazo-compound obtained as described in the first paragraph of Example 1 is coupled at 5-- I II III IV Tint oi the Diem-component (H|N-Rt) used for cupriierous Initial component Middle component making the monoazo-dyestufl serving dyestufl'on as end component cotton 1 2-(4-aminopheny1)-6-methy1benzthia- 1-amino-2-methoxybenzene 1-aminobenzene-2-carboxylic acid Greenish grey. zolie-x-sulfonic acid. I

1-aminobenzene-3-carboxylic acid Grey.

1-aminobenzene-4-carboxyllc acid Do. Aminobenzenc l-aminobenzenei-sulionic acid. 2-aminona hthalene-4:8-disulfonic a I-aminobenzcne-K-sulionic acid do Grey.

1 aigiino 4 methylbenzene 3 sulionic Greenish grey.

ac l-aininobenzcne-3-sulionic acid-amide.

Do. l-aminobenzenc-Ii-sulionicacid Greengrey. Aminobenzenenu. Grey.

Do. Grcenish grey. Green grey. Greenish grey.

The dyestuifs Nos. 1-6 of the above table corresponds 10 C. in a solution rendered alkaline with sodium carto the formula Hols 04sec.)

., 5 Bots in which A represents respectively the following radicals: 5 formula No. 1: O 0 OH x bonate with 42 parts of the triazole compound of the No.2: icon 80.3

Nb. 3: Co OH W This triazole'compound can be made byicoupling diazo tized 'i-aminobenzene-3-sulfonicacid under acid condieem? tion with 2-amino-S-hydroxynaphthaleneJ-sulfonic acid followed by oxidation with a copper salt.

The dyestufi so obtained, ,which contains a triazolc ring and two azo-linkages, is converted in the manner described in the second paragraph of Example 1 into its complex copper compound, but only one half of the quantity of the agent yielding copper is necessary. The,

cupriferous dyestuff has the same properties as the dye stuff of Example 1.

32 parts of 2-(4'-aminopheny1)-6-methylJ5Enzthi azole-.:f

cal solution of copper sulfate (cdrresponding to 50 parts I H :W N. J (I) On 1 111 -8 dyeingis continued .ior a further V2 hour at 90-95 C. The cotton is 'themrinse'd and finished in the usual man; tier. It is dyed a uniforni'gre'eni'sh greytint. V. What is claimed is: A i i I I I I. A cupriferous azo-dyestuli of the formula in which R represents a benzene radical fused to the thiazole ring in the manner indicated, R represents a benzene radical bound to the azo linkage in para-position to the thiazole ring', R- represents an aromatic radical containing at the most 10 aromaticnuclear carbon atoms, R represents a member selected from the group consisting of a benzene radical and a sulfonated naphthalene radical, and in which at least one of the radicals R and R contains a sulfonic acid group and the groups R N= OCu-- and --N=N are present-in the-l:3:4-positions of the radical R I Z A-cuprifemus azo-dyestntf of the formula of i so,.sn,o ,g the whole is heated fpr 85-1O hours at in which R represents a benezene radical fused on to the 90-9? C; under a reflux" condenser. The resulting dyestud. of the formula V.

'thiazole ring in the manner indicated, R represents a benzene radical, R represents a benzene radical, n-repre is issue in the usual time and driedy lt dissolves-f;

in water with a green coloration and dyes cotton bluish green tints. Example 4 100 parts oi cottonare entered at 40" -C into adyebath which contains in 3000 parts of water 0.5 part "of" HOsS for one hour while, raising the temperature to .90". .C.,

\C l MQN sents a whole member of at the most 2 and the groups ent in the 1 :3 :4-positions of the radical R 3. cupriferous azo dyestuii of the formula in which R represents a benzene radical and n represents a whole number of at the most 2.

4 A cuprilf erous azo dyestuff of the formula in which R represents a benzene radical containing a sub- 30, of crystallinejsodium" sulfate arejadded, 'and '6 stituent imparting solubilityin water.

10 5. The cupriferous azo-dyestufi of the formula HOzS- -N 503K 6. The cupriferous azo-dyestuff of the formula HOaS N HO=S N 000E 7. The cupriferous azo-dyestuff of the formula H038 (|)Cu-O C N=N N=N H30 s HOaS- N COOH 8. The cupriferous azo-dyestufi 0f the formula 9. The cuprifemus azo-dyestufi of the formula HOaS N UNITED STATES PATENTS 2,029,591 Schindhe'lm et a1. Feb. 4, 1936 2,390,480 West Dec. 4, 1945 FOREIGN PATENTS 719,363 Great Britain Dec. 1, 1954 UNITED STATES PATENT OFFICE CERTIFICATE 0F CORRECTION Patent No. 2,837,507 June 3, 1958 Henri Hi at It is herebfi certified that error appears in the-printed specification of the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 1, line 37, for "napthalene" read naphthalene column 5,, in the first line below the table, for corresponds" read oorrespond column 8, claim 3, the lower right-=hand end of the formula, for "R" read Signed and sealed this 25th day of November 1958,

(SEAL) Attest:

KARL H. AXLINE ROBERT C. WATSON Attesting Oflicer Commissioner of Patents 

1. A CUPRIFEROPUS AZO-DYESTUFF OF THE FORMULA 